Shopping: Real Estate |  Costumes  |  Guitars
This Issue Archived Articles Blog About Us Contact Us
SEARCH


Frank's Suspension, Part 1

New springs and dampers

by Julian Edgar

Click on pics to view larger images


 

We’ve already done the engine air intake (see Negative Boost Revisited, Part 1), brakes (see New Brakes for the Falcon, Part 1), extractors and exhaust (see Frank's Exhaust, Part 1, and the engine cam and management (see Frank's Cam Part 1); now it’s time for the suspension on our EF Falcon.

The suspension components supplier that we chose was Whiteline – a company whose products we’ve often driven and been impressed by. We asked for everything they had for an EF six cylinder and that’s just what they made available.

First-up were new springs and dampers.

Standard Frank

Click for larger image

Frank the Falcon’s standard suspension wasn’t. Rather than being fitted with the normal suspension tune, the Falcon had come from the factory with the Country Pack suspension, which raises the ride height. Now you’d think with a higher ride height (and we assume softer spring rates), the Falcon would have handled like a real bucket, especially on the Maxxis 205/65 (treadwear number: 420!) tyres fitted to the car when we bought it.

But in fact the car handled quite well. It was a bit taily in the wet - with a lateral weight transfer that could be easily felt - but the long-travel suspension soaked-up bumps that you’d have expected to throw the solid rear axle off-line. Front-end grip was always strong. In fact, on the roads on which I drive every day (rough and challenging secondary country bitumen), the Falcon was quite impressive.

Yes, believe it or not.

Ride quality? Well, it was a bit under-damped in taxing, long wavy undulations, but in general it put the bumps away without fuss or intrusion.

So when I told my wife it was time to install the suspension components that had patiently been waiting the fitment of the new brakes, extractors, exhaust, the cam and the engine management changes, she wasn’t positive. After all, we didn’t think the Falcon suspension was doing too bad a job to start with! And, further to that, we were both a bit wary of making further changes after the expensive non-event of the new engine camshaft....

Would the new springs and dampers wreck the ride, giving bumpy, harsh results that bounced the car around on these poor surfaces, resulting in less tyre adhesion and handling suitable only for dead smooth roads? It was our suspicion that it might!

Click for larger image

Anyway, here’s the ride height of the car with its standard Country Pack suspension.

Springs and Dampers

The Whiteline supplied springs and dampers comprised:

  • Front springs - # 78900A - $174 pair

  • Front dampers - # 120260 (front right) and # 120250 (front left) - $395 pair

  • Rear springs - # 71400A - $174 pair

  • Rear dampers - # 110170 - $116 pair

Note: as with all the suspension products provided by Whiteline for the Falcon, these components were made available free of charge.

With a recommended retail cost of $859, this is obviously not a cheap package. However, the dampers are Boge Turbo units and the springs (variable rate on the rear) are designed specifically to match the car and dampers.

Here are the measured specs on the front springs, comparing standard and Whiteline:

Free Length

Wire Thickness

Number Free Turns

Standard Country Pack

415

15.5

8 – constant rate

Whiteline

360

17.5

8 – constant rate

Given that the springs fit in the same space, you can see that there’s a lot less preload on the Whiteline springs (they’re 55mm shorter) but the greater wire thickness means that they’re about 1.8 times as stiff.

Here are the specs on the rear springs, again comparing standard and Whiteline:

Free Length

Wire Thickness

Number Free Turns

Standard Country Pack

430

14

5 – constant rate

Whiteline

390

15.4

8 – variable rate

Click for larger image

The new rear springs are 40mm shorter but a rate comparison cannot easily be made because of the variable design used in the Whiteline spring. In a variable rate spring of this type, the coil spacing is uneven. As a result, some coils are designed to bind, stiffening the spring at a greater rate as it deflects.

Interestingly, the Whiteline spring has 4 close-wound coils, implying that once these have coil-bound, the remaining 4 coils provide the spring stiffness. On that basis, a guesstimate would have the Whiteline coils providing the same increase in stiffness (1.8 times) as the front springs – once the progressive spring section has closed up. To put this another way, you’d expect the rear suspension to have better droop than standard but under bump to be similarly stiff to the new front springs.

Installation

We had Simon of Simon’s Car Clinic install the springs and dampers. This was a straightforward 3-hour job.

Front

Click for larger image

The front dampers are built into an assembly that includes the spring seat and a forked lower mount. (Remember in this time of near universal MacPherson struts that the Falcon uses a Short Long Arm [SLA] style of front wishbone suspension.)

Click for larger image

Removal requires the undoing of the upper mount nuts...

Click for larger image

..and the removal of the lower fork mounting bolt.

Click for larger image

Usually, a lever can then be used to push down the suspension lower arm and sway bar, allowing the damper assembly to be removed, complete with spring.

Click for larger image

However, in this case the upper ball-joint also needed to be undone to allow sufficient suspension movement to extract the spring/damper.

Click for larger image

With spring compressors applied, the old spring can be removed (to gain access to the old upper mount) and then the old mount placed on the new spring and damper.

Click for larger image

Here’s a comparison of the old and new front springs.

Click for larger image

Refitting is a reversal of removal.

Rear

Click for larger image

The rear spring and damper swap is similarly easy. The upper damper mount bolts are accessible from inside the cabin...

Click for larger image

...and undoing the lower damper mounting bolt allows the damper to be withdrawn. Unlike the front, the spring is not mounted on the damper.

Click for larger image

Spring compressors can easily be used to shorten the rear spring, allowing it to be removed.

Click for larger image

The new rear spring was inserted (it was shorter so didn’t need to be compressed)....

Click for larger image

... the bump rubber swapped over...

Click for larger image

...and then the new damper installed.

Click for larger image

Finished!

Ride Height Changes

This shows the measured ride heights, in centimetres, before and after the installation of the new springs.

Standard Country Pack

Whiteline

Front

68.5

65.5

Rear

69.5

64

Click for larger image

The heights were measured from the guard lip to the ground. So the front dropped by 3cm and the rear by 5.5cm – no, we’re not sure why is that is so either!

On-Road Results

So have the new springs and dampers destroyed the ride? Nope!

Even by just bouncing the Falcon up and down on the spot by hand, it’s obvious that the new suspension is not the rock-hard aftermarket design that was once so common. With the variable rate rear springs, the rear feels in fact almost soft, and the front is definitely not very hard.

On the road, the springing and dampers are obviously firmer, but unremarkably so. Within a day of driving I could literally forget that they’d be changed – this is not a suspension where every time you get into the car you lament its harshness. In fact, the only criticism that I think can be made of the ride at all is that it can be a little pattery on corrugated style surfaces – I wouldn’t run this suspension with ultra low profile tyres.

And the handling? Does the Falcon now leap from bump to bump? Nope!

Click for larger image

On smooth surfaces the weight transfer and body roll are much reduced. But to me even more impressive is the way in which the Falcon can now get its power down to the road when exiting second gear corners. Previously, the bountiful mid-range torque and lack of a limited slip diff caused the corner exit speeds to be limited by how much power could be applied before inner wheelspin occurred. But with the Whiteline springs and dampers, the inner rear wheel has far better grip – those progressive rate springs allowing better droop.

At higher speeds on smooth surfaces there’s now a fraction too much power oversteer – I’d rather at 90 or 100 km/h that the car started to push into understeer than oversteer. Again, that’s paradoxically because the inner wheel is better gripping – the power is no longer frittered away with inner wheelspin (yes it used to, even at those speeds!) but instead is put down to the ground, so provoking power oversteer. (However, this tweaking of handling will easily able to be addressed by the adjustable anti-roll bars, which are to be fitted next.)

And on rougher roads? There I think the suspension is extremely impressive. In fact, along just the same road that saw a Nissan 350Z jumping around, traction control light flashing as the overly-hard suspension rapidly got way out of its depth, the Falcon just powered along. The slightly pattery ride feeling is simply not transferred to poor traction in these conditions. Instead you can feel the springs and dampers working hard – the dampers working bloody hard! – but the package performs extremely well.

So what deficiencies can now be felt in the suspension? In addition to the slight bias I’d prefer to understeer rather than oversteer, power on/off applications in constant radius corners can cause the rear-end to steer. This is a known characteristic of EF Falcons but previously I’d not felt it. (Perhaps it was being masked by the more pronounced lateral weight transfer.) And although rear-end grip has been improved, I think it could be a bit better again – again that should be able to be tweaked with the anti-roll bars. Finally, there is some rear bush noise which previously could only just be heard but is now quite pronounced.

Conclusion

The Whiteline spring/damper package is not cheap - but it really delivers in terms of providing good ride quality and excellent handling on all surfaces. Highly recommended.

Next: fitting Whiteline adjustable anti-roll bars

Contacts:

Whiteline Suspension – www.whiteline.com.au

Simon’s Car Clinic – Tamborine (Queensland) – 07 55436155

The Whiteline suspension components were supplied courtesy of Whiteline

Simon’s Car Clinic was paid at normal commercial rates

Did you enjoy this article?

Please consider supporting AutoSpeed with a small contribution. More Info...


Share this Article: 

More of our most popular articles.
Unique and cheap modification to keep the car longer in lean cruise

DIY Tech Features - 7 April, 2008

Giving the Insight a Good Driver

Stopping vibration in its tracks

DIY Tech Features - 15 December, 2009

Designing Rubber Mounts

Getting planning approval

DIY Tech Features - 7 February, 2012

A New Home Workshop, Part 3

The very first production turbo car - the Oldsmobile Jetfire

Special Features - 7 June, 2003

The Early Days of Turbo Part 4

Insulating the intake manifold from the head for more power

Technical Features - 4 June, 2008

Cool Stuff - Manifold Insulators

A revolutionary fuel saving device that works

Columns - 25 August, 2009

FuelSmart, Part 2

Clearing the space

DIY Tech Features - 10 January, 2012

A New Home Workshop, Part 1

Dressing MIG welds made in car bodywork

DIY Tech Features - 3 June, 2014

Dressing MIG Welds

The most important aircraft ever?

Special Features - 15 December, 2009

The Wright Flyer III

How good were they?

Special Features - 15 June, 2010

The First Holdens

Copyright © 1996-2020 Web Publications Pty Limited. All Rights ReservedRSS|Privacy policy|Advertise
Consulting Services: Magento Experts|Technologies : Magento Extensions|ReadytoShip